Roofing material



1931- H. L LEVIN 1,789.443

ROOFING MATERIAL Filed June 5, 1926 ,2 Sheets-Sheet l 0 a 3 I o 42 29 39 "YEW W fi k 5 Z 440 24 x45 ATTORN EY$ Jan. 20, 1931. H. L. LEVIN 1,739,443

ROOFING MATERIAL Filed June 5, 1926 2 Sheets-Sheet 2 X? Z J 'S ATTORNEYS) Patented Jan. 20, 1931 UNITED. STATES PATENT OFFICE HAROLD LESTER LEVIN, 0'! PASSAIG, NEW JERSEY, ASSIGNOR, BY MES NE ASSIGN- MENTS, TO ANACONDA SALES COMPANY, OF NEW YORK, N. Y., A CORPORATION OE DELAWARE ROOFING MATERIAL This invention relates to prepared roofing products which comprise a base or foundation layer, to the surface of which is applied a coating of a granular substance which is used to protect the base against wear, and for other purposes. The invention has to do more particularly with a new granular wear material of an improved type for use in such roofings, and the invention comprehends not only the granular material and the roofing roduct in which it is incorporated, but also a method by which this granular material ma be produced.

repared roofings now in common use are but that type of roofing which is manufactured tothe greatest extent consists of a foundation layer in the form of a felted fibrous web which is impregnated with a water-resistant material, such as asphalt, and then given a coatin of an asphaltic substance, over which is app ied the granularlayer. The granular material most frequently used for the purpose consists of crushed slate or other mineral substances, and these substances are applied by being strewn over the asphaltic coating on the base while the latter is still tacky and then pressed into the coating to be partially submerged therein and held by the coating when the latter sets. 0

The use of the granular la er is highly desirable for many reasons. ts presence improves the appearance of the roofing, concealing the asphaltic coating on the base, and giving the roofing a texture, as well as increasing its resistance to fire. The granular materials which are suitable for the purpose are obtainable, however, only in a relatively narrow range of colors, and frequently these colors are not suitable for use in connection with thestructure on which the roofing is to .be applied.

Metal roofing, as is well known, has certain features of advantage, such as resistance to fire and great durabilit but it is objectionable because the meta transmits heat rapidly and a satisfactory roof requires the use of additional layers of insulating material beneath the metal. The cost of the material used in a roof made of metal is therefore uite high, and the cost of laying is also high, ecause of the care with whlch the roofing must be laid in order to secure a waterproof structure. A roof covered with a metal such as copper, however, is highly satisfactory once installed, because its life is practically indefinite and the copper weathers upon exposure and takes on an attractive appearance, due to the patina which forms on its surface.

The present invention is directed to the provision of a prepared roofing which has a relatively low cost, is capable of being produced at a high output rate, and has the desirable qualities of both metal and granular surfaced roofings without their disadvantages. The new material includes a base or foundation layer of a suitable non-metallic material rendered Water-resistant by impregnation with compounds such as, asphalt and having its surface covered with a layer of granular substance which gives the roof the appearance of metal, due to the fact that each of the gran-v ules is encased or plated with a metal film. These granular particles may be of any suitable material, such as crushed slate, for example, and they are coated with metal, preferably by an electrolytic process, the surface of the particles having first been rendered electroconductive by the application of a suitable conductive substance, such as graphite. Each particle receives a thin film of metal during the electrodeposition, and the metal film is so thin that only a relatively small amount of metal is required in plating the granules used for coating a large expanse of the base.

The coated granular particles are applied tothe surface of the base and aflixed thereto inany suitable manner, but preferably by first coating the base with an adhesive substance which will harden on setting. Asphaltic material which has a melting point such that it will withstand solar heat, may be used for this coating and after the application of the coating and while it is still tacky, the

metal plated granules are sprinkled over it coating are reduced to a minimum, and ac quentl has the desired appearance of metal,

and w en a metal such as copper" is used the portions of the film on the particles which are exposed, weather in the ordinary manner and take on the usual appearance of Weathered copper. The amount of metal em- 1ployed to coat the particles is so small that the nal cost of this product is not materially greater than that ofthe ordinary grit-surfaced roofing, so that the new' material has the desired cheapness of the ordinary gritsurfaced product, as well as the desirable appearance and weathering qualities of an allmetal roof.

The present invention includes not only the new granular material and the roofing in which it is incorporated, but also a method by which this granular material may be conveniently prepared at a low cost.

For a better understanding of the invention, reference will be made to the accompanying drawings, showing the new products and apparatus by which the new granular material may be produced. In these drawings Fig. 1 is a view in vertical cross-section showing one form of apparatus for producing the new granular substance,

Fig. 2 is a similar view of a modified form of the apparatus,

Fig. 3 is a view in section of a piece of the roofing material, showing the new granular material applied,

Figs. 4 and 5 are enlarged sectional views of two types of the new granular material,

Fig. 6 is a vertical sectional view through an apparatus for continuously producing the new material,

Fig. 7 is a transverse section-through the a paratus of Fig. 6,

Fig. 8 is a sectional view through the shaft of the apparatus, and

Fig. 9 is an end view of the shaft showing a contact member.

With reference now to the drawings, the new roofing material is shown in Fig. 3 as consisting of-a foundation layer or base 10 of any suitable type. A base which has been found highly satisfactory in ordinary use, and which is now most generally employed in products of this character, is a felted fibrous web impregnated and rendered waterproof by means of asphaltic compositions. In the manufacture of the new material, the web is drawn from a supply, passed throu h vats or tanks-in which the hot asphalt is contained, and in the course of passage through these tanks the web is impregnated by the asphalt which enters the interstices between the fibres. From the impregnating tanks the web passes to a coating apparatas where a coating layer 11 of suitable material 18 applied. The coating layer most commonly used is blown or oxi ized asphalt which has a melting point such that it is capable of withstanding solar heat. In the manufacture of ordinary roofing the coated web is next led through devices where granular materials ofa suitable kind are strewn over the surface of the web, pressin'c then being applied to partially embedthe granules in the surface of the asphalt coating while the latter is still tacky. The web, after cooling, is then led to cutting devices which cut it into units of and size.

The new material illustrated in Fig. 3 consists of the coated web, to the surface of which is applied a layer 12 of granular material,'the individual granules of which are covered with a metal coating. Such granules are distributed over the surface ofthe web ust after the latter has been coated and while the coating is still tacky, and are embedded in the coating in the usual way. The granular material is supplied in such quantities that after partial submergencc in the coating, the adjacent granules are in contact and as is shown clearly in Fig. 3, the base is thus covered with a substantially continuous coating of metal, the asphaltic coating 11 being practically invisible through the interstices between adjacent particles.

In Figs. 4. and 5 there are shown two granules of the new material on an enlarged scale. The granule 13 is coated with a layer of metal 14 and this coating may be easily applied by an electrolytic process. Since the granule, or at least the surface on which the coating is to be deposited, must be electroconductivc, it has been found most convenient to employ granular material of electroconductive qualities, as, for example, the granules may be of carbonaceous materials, such as crushed coke, or crushed calcined coal, or the like. These granules are then introduced .into plating tanks and receive a thin film of metal by a process presently to be described. If the granules are not electroconductive, then the surface on which the metallic coating is to be applied must first be rendered conductive. Such a granule is illustrated at 15. It is of any suitable nonthe desired shape ill) metallic, non-conductive material, such as the granules with an adhesive, so that the conductive material will adhere. For this purpose numerous adhesives may be used, such, for instance, as spirit varnish or an aqueous asphalt emulsion.

Another method of preparing the granules is to coat them with coal tar pitch or other similar bitumen, either molten or in dispersed form, and then to carbonize this layer in any suitable way, as by passing the granules through a lead bath. A similar result may also be obtained by surfacing the mineral particles with an oxidized binder, such as linseed oil. followed by a coating of a suitable metallic salt capable of reduction to produce the metal. For example, lead suboxide may be employed and upon exposure of the coated granule to heat, the lead salt film is reduced to. metallic lead. Various other methods for producing the conductive coating may also be used. In any of these methods the purpose is to form a conductive film on the surface of the non-conductive granules, so that a metallic film 14 may be applied thereto by electrodeposition although the application to the granules of metallic salts which may be reduced to yield the metal, may in itself provide a coating of metal of sufficient thickness. In addition to the methods above described, the new material may be produced by spraying molten metal on the granules, or by other similar methods of applying thin films of metal.

For the purpose of producing the film on the granules, the granular material may be treated either in batches or in' a continuous operation. In Fig. 1 there is shown an apparatus by which the material may be treated in batches.

The apparatus here illustrated includes a tank 17 of any convenient form, and the tank or vat may be of Wood or of metal insulated on its inner surface to prevent deposition. The tank is provided with a sheathing 18 of metal near its lower end which is connected by a lead 19 to the negative side of a source of energy. This sheathing 18 forms the cathode. The anode 20 may be of any convenient form connected by a lead 21 to the positive side of the source of energy.

Within the tank is a body of electrolyte 22 and the tank is provided with a pump 23 having an intake 24 near the top of the electrolyte. the pump withdrawing electrolyte from the top of the cell and introducing1 it t in at the apex of the conicalvat at 25. Wi

the vat, above the apex, meansare provided for insuring circulation, and for this purpose a cylinder 26 mounted on arms 27 within the vat may be employed. The body of granular material is introduced into the apex of the Come by means of the pump and is thenthrown out through the cylinderto the side walls, as indicated by the arrows. The material collects on the side walls and at once barrel.

becomes electrically connected to the cathode of the cell, covering the latter. The metal is thereupon electroplated from the electro lyte upon the conductive surfaces of the granules, and this plating is carried on until a film of the desired thickness is built up whereupon the granular material is removed and additional quantities introduced. The continuous circulation of the electrolyte causes an agitation of the granules, which permits them to be plated on all surfaces.

In Fig.2 there is shown another form of apparatus in which the material is treated in batches. This apparatus includes a tumblim barrel 28 mounted to rotate on an incline shaft 29 supported in bearings 30 and 31 in any suitable manner. These bearings are pivotally supported on standards 32 and 33 and the barrel has an open end 34 through which the electrolyte and granular material -may be introduced. Through the opening extends a rod 35 carrying anode 36 which may be of any convenient form and is here shown as cast of toroidal form slotted so as to fit on the rod 35. The rod is supported .at its upper end in a standard 36 and is conof energy. \Vithin the barrel, on the inner face thereof, are blades or addles 41 serving as agitating means, the arrel being rotated by means of a pulley 42 on the end of the shaft 29.

In t barrel is filled by withdrawing the anode and cathode through the open end of the The standard 33 acts as a supporting leg for the shaft 34 and carries bearings 3O pivotally mounted at its upper end. This supporting leg may be swung to one side and the barrel may then be swung downwardly,'the bearing 31 pivoting in the upper end of the standard 32.

The electrolyte and a suitable quantity of granular material 43 are then introduced into the barrel, and it is swung to normal position and the anode and cathode inserted. As the barrel rotates, the granular material is agitated but lies connected electrically to operation of the apparatus, the

the cathode. Deposition of the metal takes I place on the granules, and as soon as the metal film has been built up to the desired thickness, the process is continued and the barrel emptied.

Figs. 6 to 9 inclusive, are difl'erent views of continuous apparatus for applying the metal layer to the granules. This apparatus includes an electrolytic tank 44 of considerable length, having an inlet pipe 45and an overflow lip 46. Within the tank is a rotatable cylinder 47 mounted on spiders 48 on a hollow shaft 49 supported in suitable bearings 50 in standards 51 outside the' tank. This shaft carries a pulley 52, which may be driven frdm any convenient source of newer. On the inner walls of the cylinder are spaced helical bafiies 53 mounted on insulated mountings and arranged in rows, with the bullies of each row connected in series with each other, as indicated at 54. Each row of baflles is connected by a connection, shown diagrammatically at 55, to one of a plurality of segments56 placed within the hollow shaft 49, these se ents being insulated from the shaft an from each other. The segments extend out beyond the end of the shaft carried in one of the bearings 50, and the exposed portion of the segments forms a commutator 57. Against this commutator bears a, brush 58 on a spring mounting 59 supported on a bracket 60 on the standard 51, and a lead 62 connects the brush to the negative side of a source of current. The brush is arranged to bear against the bottom se ment of the commutator, and it will accor i'ngly be seen that as the cylinder 47- is rotated,

the row of bafiies 53 in the bottom of the cylinder is connected electrically as the cathode, and when this row of ba es is carried around so that its associated segment is out of contact with the brush, the battles of the row become inactive.

The spiders 48 carry anode bars 63 held in place by spacers 64, and a brush 65 on he standard 50 bears against the contact ring 66 by which current is supplied throu h {)he shaft 49 and the spiders 48 to the anode ars.

The granular material placed in the hopper 67 flows through a s out 68 and is discharged into one end of th e cylinder. Within'the hopper is a rotary element 69 which keeps the granular material agitated and the flow is controlled by a gate 70. Flowing into the cylinder, the material lies in the bottom of the latter, as indicated at 71, and in this position covers a row of baflies lying at the bottom of the cylinder. The anodes 72, which are placed nearest this row of battles, lie beneath the level 73 of the, electrolyte in the tank 44 and current flows through the electrolyte, causing a deposition of the metal upon the granules in contact with the bafiie cathodes. The other anodes, as shown in Fig. 7, are out of the solution, and the anodes adjacent the one lying within the solution .lie above the level of the latter, and the bafiie cathodes of the row adjacent that which is connected electrically to the brush 58 are inactive, since they are not connected to the source of energy. Accordingly a plating action takes place on the granules in the bottom of the cylinder, and the action is most pronounced erably made of wood or of metal insulatedso that no plating action can take place upon it, and it is preferably perforated with small perforations so that the electrolyte can enter the cylinder but the granules cannot leave it. If the cylinder is constructed of metal, the spiders 48 should be insulated from the shaft and similarl the anodes should be insulated from the splders, so that short-circuiting is prevented. The electrical connections by which current is supplied to the anodes and cathodes may be di erent from those shown, but the purpose of the arrangement 'is to bring about a flow of current from the anodes through the solution to the cathodes, which lie beneath the granular material, no current being withdrawn from the cell through cathodes which are not fully or partially covered by the granular material. In this way dating of the metal u on the cathodes is argely avoided, and t e entire deposition takes place on the surface of the granules.

It will be seen that the application of the metal to the surfaces of the granules is a relatively simple process and since only a thin layer of the metal is required to produce the desired result, the cost of the metal and of plating it upon the ranules is relatively small. Instead of emp oying a plating operation, it is possible to apply the metal in the form of a powder suspended in a suitable vehicle, coating the granules with this suspension, as, for example, by a tumbling operation. The electrolytic application of the metal, however, is much simpler and less expensive. After the metal film on the granules has been built up to the desired thickness, the granules are withdrawn from the electrolytic tank and then, after washin to remove traces of the electrolyte, are rea y for use. They are deposited on the surface of the web by means of ap aratus commonly employed for the distribution of the grit and are embedded in the asphalt coating layer by pressure in "the usual way. It is desirable that the parin. Such portions of the granules as are ex-- posed, give the roofing product the appearance of being coated with metal, and when copper is employed this metallic layer takes on the usual greenish tones which are considered so desirable in sheet copper roofs.

The new product therefore gives the roof the desired appearance of being coated with metal and is much less expensive to produce. Also it is much easier to lay, because the coated bases may be cut into individual or strip shingles in the same manner as the present prepared roofings, and these individual elements laid in overlapping courses in theusual manner. The labor involved in laying a roof in this way is thus much less than that necessary to roduce a water-tight roof of sheet metal e ements.

I claim:

A, sheet material suitable for roofing and other purposes, which comprises the combination of a foundation layer and a coating of no granular material aflixed to the surface of the foundation layer, the individual granules being coated with a film of metal.

In testimon whereof I affix my signature.

H ROLD LESTER LEVIN. 

